Steam-boiler.



C. W. CROWELL.

STEAM BOILER. APPLICATION FILED JUNE I0. 1912. RENEWED OCT. 31. 1914. 1,159,180.

' Patented Nov. 2, 1915.

2 SHEETSSHEET I- INVENTOR d/zfi/rzfifl a/zz fu WIT M58858 I/"TORNEVS c. w. CROWELL.

STEAM BOILER. APPLICATION FILED JUNE 10, I912- RENEWED OCT-31.1914.

I Patented NOV. 2, 1915.

'2 SHEETS-SHEET 2.

WITNESSES ATTORNEYS \IOLUMUIA PLANDIJRAPH 60., WASHINGTON, D c.

UNITED stra rns PATENT orrroni.

CHARLES WAKEFIELD CROWELL, OF KNOXVILLE, TENNESSEE.

STEAM-BOILER.

v Specification of Letters Patent.

Serial No. 702,754. Renewed October 31,1914. Serial No. 869,697.

To all whom it may concern.

Be it known that I, CHARLES a citizen of the United States, and a resident of Knoxville, in the county of Knox and State of Tennessee, have invented certain new and useful Improvements in Steam- Boiler's, of which the following is a specification.

My invention relates to horizontal or approximately horizontal steam boilers, and more particularly to steam boilers which are made parts of railway locomotives.

The object of the invention is to provide a boiler embodying a fire box and adjacent portions arranged for an open bottom fire box with direct communication to the ash pan without having water legs or downward and outward extensions from the cylindrical shell of boiler, economy in construction, great strength, convenient repairing and for equalizing the strain, expansion and contraction. I

:This application is a division of my ap- 619,051, filed April 5,

In the accompanying drawings which arev for the purpose of illustration only: Figure 1 is a vertical longitudinal section of a boiler and fire box embodying my invention; Fig. 2 is a cross section on about the line 22 of Fig. 1; Fig. 3 is a rear end'ele vation, partly in section: Fig. 4c is a detail perspective view of the mud frame with some of the stay rods in connection with the cross portion thereof; Fig. 51s a detail vertical longitudinal section enlarged, showing the means for staylng the flue sheet of the fire box to the rear head and extended shell of combustion chamber. 7

D is the shell of the boiler. This is of an approximately cylindrical form.

N is the back head of the. boiler. This is flanged forward along its outer edge and }the flange riveted to the rear edge of-the boiler shell in the usual manner. being flat, the bacl ,head, N, is dished, the

Instead of middle portion extending backward. This is for a purpose to be hereinafter stated.

J is the mud ring or frame. This is used for forming a fire box-opening through the lower portion of the boiler shell, said shell being cut away over the area covered by the mud ring. Said ring consists of a front portion,. 4, curved downward to conform to the curvature of the boilerv shell, and 5, 5,

WV. CROWELL,

and is riveted thereto.

afterward remove a circular fire box opening.

portion 'end, J of the mud ring,

Patented Nov. 2, 1915. Original application filed April 5, 1911, Serial No. 619,051. Divided and this application filed June 10, 1912 are the straight sides of said ring, and

J J are the ends of said ring. Said ends are turned outward and upward to conform to the curvature of the boiler shell'and to bear against the inner face of the back head of the boiler.

The front, curved portion, 4:, of the mud ring has an inner flange,

7, along its lower edge and extending forward over the inner face of the adjacent portion of the the latter. the sides, 5, of the mud ring is an upward and outward turned outer flange, J which is parallel to and bea'rsagainst the inner face of the adjacent portion of the boiler shell boilershell and is riveted to and 9. maybe continuous and constitute a s ngle flange. In this manner, said mud ring or frame for the fire box opening of the boiler shell.

When the back head of the boiler is completed, it does not extend below the mud frame; but for convenient construction, it is preferable to cut it in full circular form and the surplus segment below the mud ring. In the back head is formed is formed on said head around said opening and directed horizontally rearward. The

mud ring and said flange, N form a seat forthe fire box shell, A. Said shell is horizontal and approximatelycylindrical and concentric to the boiler shell; but the lower is cutaway to make an opening downward through the mudring. A circular flue sheet, D extends across theforward end of the fire box shell and has around its periphery a rearward directed flange, 12, restingagainst the inner face of forms a border or framing A flange, N

Along the lower edge of each of 1 Saidflange, 7, J

the firebox shell and is riveted thereto. The

upper edge of the front portion, 4:, of the mud ring has a flange, J extending rearward beneath the flange 12 of'the flue sheet and the scarfed corners of the fire box shell,

- and being riveted along said portion. Along the'upperedge of each side piece, 5, of the mud ring, a flange, J extends inward and downward along and parallel to the adja cent portion of the fire box shell and is'riveted thereto. On the inner portion of each a flange, 9, is

turned forward between and parallel to the jouter faoe of the fire box shell'andthe ad- 75 G is the ash pan communicating with the v fire box opening. 5

jacent portion of the flange, N of the back head, N, of the boiler, and is riveted to said fire box shell and said flange. The rear portion of the fire box shell is flared outward so as to give the portion of said shell within the flange, N a larger diameter than the diameter of the fire box shell forward of said flange, in order that the entire fire box shell, and any rivet or bolt heads projecting therefrom may readily pass said flange, N for the insertion and removal of the shell. A back head, A, extends across the fire box shell about opposite theinner portion of the boiler back head and has a flange, A extended backward and lying against the inner face of the fire box shell and being riveted to the latter and the flange, N by rivets extending through said flanges and said shell. Said fire box back head has around its center a backward turned flange, 18, surrounding the fire box door opening. Immediately forward of the back head, A the fire box shell, A, has water ports, A Forward of said portsis the fire box door sheet, A, extending across the interior of the fire box and having along its periphery forward turned flange, 21, bearing against the inner face of the fire box shell and riveted thereto. At its middle, said door sheet has a circular flange extending rearward across the space between said sheet and the back head, A, and through the latter and against the flange, 18, and riveted to the latter by rivets which are perpendicular to the axis of said flanges. The flange in door hole of back head, A, may be turned forward or backward for connection with the flange of door sheet, A. The back head A, and the door sheet A, are preferably continued downward below the adjacent ends of the mud ring far enough to complete the circle, sheet metal extending around the said heads forming an attachment to the flanges A and 21, inclosing the lower portion of the water space formed between said heads and the adjacent edges of the mud frame.

If so desired in order to save a waste in material the fire box may be cut off just below the mud frame, and an extra sheet with the ends tapered let in between the cut off ends of fire box and the heads extending to top edge of mud frame, and secured the same as if the fire box shell extended all the way around the heads. The heads, A and A, may be cut off at any desired point below the mud frame and a solid bar of iron,

M, riveted between them, the bar being made thick at each end and shaped to fit the connection and the fire box shell extending a little below the mud frame, the mud frame and fire box being plugged to lower side of bar where rivets are not convenient to be placed.

The space between the fire box back head and the fire box door sheet receive water from the main boiler space through the water ports, A of the fire box shell. Flues, D, of any desired form extend from the portion of the fire box flue sheet above the grate forward to the usual front flue sheet D Any number of T irons 36, are riveted to back head N, fro-m top of back head around each side to any desired point above mud frame J with stay rods 25, connected to 'l' irons extending forward and obliquely outward to the boiler shell D Any desired number of stays, J, extend approximately perpendicularly to the fire box axis from the fire box shell upward and around to the boiler shell. Any desired number of stays, 27, extend horizontally from the fire box door sheet, A to the fire box back head, A. Any desired form of grate, B, is placed across the opening which is inclosed by the mud ring. The grate may be supported on bars or plates, secured along the inner face of the lower portion of the fire box shell opposite the flange, J of the side portions, 5, of the mud ring, by means of rivets or bolts extending through said plates and said flanges.

The portions of the boiler shell at the sides and front of the fire box opening in said shell arenot off-set nor extended downward or outward. On the contrary, they are left in the general perimeter of the boiler shell, so that the mud ring is within the perimeterof the boiler shell. This avoids the unequal heating and unequal strains which are present when such portions of the boiler shell are off-set or extended downward. Such unequal heating and unequal strains, when present in a boiler, cause cracking and breaking. Furthermore, this arrangement of the .mud ring within the perimeter of the boiler shell permits the use of stays 25 to extend from the back head N of the boiler shell, forward to the boiler shell in front of the fire box, and over and around each side of the fire box as low as six inches above the mud frame. The mud frame construction enables me to make the fire box and the boiler shell surrounding the fire box approximately arc shape in cross section, whereby an open bottom fire box is formed in an approximately cylindrical boiler shell, having all of the good features of a round boiler shell and a round fire box, and none of the bad, and having all of the good features of the ordinary open bottom fire box and none of the bad. It also enables me to make the fire box any desired diameter in a given size boiler shell surrounding the fire box, simply by increasing or decreasing the width of the mud frame and the back head of boiler shell to suit the size of the fire box desired, and in this construction the stay bolts leading from the fire box shell to the boiler shell may all be made an equal length if so desired, and

the water space between the fire box and boiler shell may be made any desired width. In the use of my fire box, .mud frame, and boiler shell extending over and around the fire box, the fire box may be made any desired diameter in a given size shell by increasing or decreasing the width or height of the mud frame without changing the distance from the top of the fire box to the top of the boiler shell. being arc shape in cross section makes it possible to heat the air passing through the grates before it has chanc to strike the sides of fire box, which avoids unequal expansion and cracked side sheets. The large water space affords alarge body of hot water for the cold water to mix with when cold water is put into boiler, insuring the temperature of water to be more equal at all times than in other boilers with narrow water space, and as cold water goes to the bottom, the fire box will not become chilled, causingunequal expansion and leaks at the stay bolts as in boilers with water legs extending below the cylindrical shell.

The stays from the mud ring to the boiler shell and from the back head of the boiler to the boiler shell may all be inserted before the fire box shell is put into place. This allows ample working room, being practically outside work, and repairs can be made conveniently from the inside. i

The circular cross sectional or arc shape form of the fire box shell and the boiler shell surrounding the fire box,'with a mud frame connection, simplifies the construction in the bottom and at the rear end of the boiler, and facilitates the insertion or withdrawal bodily of the open bottom fire box through the back head of boiler shell, without removing the mud frame or the back head of boiler shell, or any of the stays of either. In ordinary types of open bottom 'fire boxes the boiler shell must be disconnected at forward end of'fire 'box, or the back head of boiler shell and its staysbe removed together with the mud frame, in order to remove the fire box, some of them haveto be removed from their foundation "in order to remove the fire box from the bottom, in this case the mud frame is also removed.

'ldy firebox may be removedbodilytogather with the fiues, by cutting the fiues off at their forward ends, drilling stay rods J from the fire box end and cutting the rivets K from flange N of back head as well as the rivets securing the bottom of the flue sheet D and he fire box shell to the mud frame. In some cases, it may be desired to remove the fire box shell-and leave the fiues and flue sheet in position. In this event, the stay rods J are drilled from the fire box shell, the rivets K removed from flange N of the back head N, the rivetheads Ire- The fire box moved from the fire box shell connecting to [the flange 12 of flue sheet I) and the rivets connecting the fire box shell and flange J of the mud frame. It will also be noticed that the mud frame J J can be removed without removing the fire box or the boiler shell by springing the rear-ends together, enough to'clear the back head, it can be easily removed.

The door sheet 18 or the staying 27, either before or after the fire box is inserted. It is preferred to do the riveting 18 and the staying 27 before the door sheet-A. and the back head A. are inserted into the fire box, they may then be placed in the fire box and the riveting 21 be done. The flue-sheet D may then be placed in and the flange 12 riveted to the 'fire box shell. The fire box is then inserted and riveted to flange J and J 4 of the mud frame, and to the flange N of the back "head N, and the flange A of the door sheet. 1 g

Theflue sheet 1) has ordinary staytubes extending forward under the heating flues, supporting the space between the combustion chamber and edge of said flue sheet from the top of fire line downward.

The fire box'shell is approximately arc shape in cross section throughout its length, except the part that forms the surrounding for' the water wall in rear of fire box, the front corners being scarfed thin to form a joint between the mud'frame and the flue sheet. I 3

Should it be desired, instead of having the fire box shellextending all the way around the inner and outer water space sheets in rear of fire box, the heads may be cut off below the line of grates, anda solid barof iron rivetedjbetween said heads, extending across toeach s1de over the flanges of the' side wings of main mud frame, said bar to be'inade heavy at'each nd, and shaped to fit between the heads on front and rear side, and-to the cut off ends of the fire box shell on the bottom, the fire box shell resting be-. tween the mud frame wingsand thesolid bar and riveted or plugged together and enough of the fire box shell extending out on they ends ofbar to be plugged to bar.

The fire box shell has a flue sheet in its forward end, the corners of fire box are scarfed thin, and extend down far enough between flange of mud frame and flange of flue sheet tobe riveted, the fire box shell and flue sheet flange, is riveted together above mud frame, and the flue sheet and mud frame flanges are riveted together between the scarfed corners of fire box, the flue sheet, fire box shell, and mud frame riveted together in the lap or scarfed ends.

In cases where a combustion chamber is A and the back head of fire box 1 'may be inserted or withdrawn bodily without interfering with the rivets not used in connection with the flue sheet of the fire box, any desired form of staying be employed for staying the flue sheet and the front portion l of the mud frame forward to the shell of boiler.

The fire box shell extends farther back than the rear end of the boiler shell, and the back head of the boiler shell is bumped out or tapered rearward from the outer flange connecting to the boiler shell enough for th inner flange to be secured to the end of the fire box shell, this allows the water space heads to be placed inside of the fire box shell far enough-back to allow the flange of the inner head or door sheet to be placed perpendicularly with the flange of the back head of the boiler shell, which allows the stay bolts from the boiler shell to the fire box shell to extend perpendicularly from the boiler shell to the fire box shell, and allows them to be equally spaced in both the fire box and boiler shell, with each row the same distance from said flanges and each row the same length, in this construction,it enables me to stay the boiler shell the width of the rear water space farther back than ordinary boilers are stayed. The fire box shell being extended rearward from the door sheet is also important as the water space can be made any desired width be tween the door sheet and back head of the fire box without interfering with the proper staying of any part of the boiler, simply by tapering the back head of the boiler shell from its outer flange at boiler shell connection rearward to the inner flange for the connection with the end of the fire box shell. This extension of the fire box shell acts as a stay, and at the same time admits the circulation of water between the door sheet and back head of fire box, making a very strong structure and equalizing the strain, and simplifies the construction of the door sheet and back head of the fire box so that they may be withdrawn bodily without removing the stays and replaced the same way or they may be removed separate, the water space is limited in rear end of ordinary fire boxes owing to their construction.

The front portion 4 of the mud frame has stays J 2 extending forward therefrom for securing the mud frame to the boiler shell. Ordinary T irons may be secured to the rear ends of stays J and to the mud frame, mak ing the same construction as is shown on the back head N. The sides 5, 5, of the mud frame has stays J extending perpendicular therefrom to the shell of the boiler for securing the mud frame and boiler shell together, ordinary T irons may be secured to the boiler shell and to the sides 5, 5, of the mud frame and the stay rods J secured to the T irons, if so desired.

The mud frame and back head of boiler shell are riveted and stayed to the boiler shell before the fire box is inserted. The door sheet and back head of fire box may be riveted around door hole, and stayed together, then be placed in fire box and the door sheet riveted to fire box, after the flue sheet has been riveted in, then the fire box may be inserted and riveted to the flange of back head, and mud frame which riveting and staying is all outside work.

In this construction of the fire box, mud frame and the boiler shell surrounding the fire box, th boiler shell may be made any given diameter, and the water space between the boiler shell and fire box on the sides may be made the same width as the water and steam space above the fire box in which the fire box would be located in the center of the boiler shell, but in the same given diameter boiler shell, the fire box may be made a much larger diameter, simply by leaving enough room above the fire box for water and steam space, the fire box may be enlarged and the width of the mud frame and back head of boiler shell reduced to suit the diameter of the fire box until the mud frame is only about four inches wide, while in other open bottom boilers the fire box must be a certain size in a given size boiler shell.

The outside shell of the boiler surrounding the fire box is approximately are shaped in cross section from the front portion l of the mud frame, rearward throughout its length, said outside shell may be connected to any straight or tapered barrel or shell of boiler forward of mud frame, or on line with portion 4 of mud frame, or in rear of said portion, if so desired.

Should it be desired to remove the mud frame bodily, without removing any other part of the boiler, the rivets and stays are cut loose from the mud frame and the rear ends of the mud frame sprung together far enough to allow the turned up end J to clear the back head L. It may then be removed from the rear, and inserted in the same manner.

My fire box, mudframe, and boiler shell extending over and around the sides of the fire box may be used connected to any desired form of boiler shell extending forward therefrom, which has heating fiues extending through it, and an approximately circular opening at its rear end for the connection around said boiler shell and mud frame. In my fire box construction the mud frame and the boiler shell extending over and around each side of the fire box may be connected to a boiler shell extending forward from the fire box the same diameter as the shell extending over and around th fire box, if used as a stationary boiler, but in locomotive boilers, it is preferred to connect it to a tapered shell or frustum, the location and shape of the tapered connection being governed by the height of the cylinders, the height of the driving wheels, the diameter of the boiler shell in front and rear 01 said tapered shell or frustum. I

I claim as my invention: a 1. The combination with a boiler having an opening for a fire box shell, a fire box shell having its rear end of larger diameter than the portion forward'oi' said end and said end extending through and being secured in said'opening, substantially as described. V

2. The combination with a. boiler shell, of a back head extending across said shell and having a circular opening for a fire box shell, a substantially cylindrical fire box shell having its rear end of larger diameter than the portion forward of said end and said end extending through and being secured in said opening, substantially as described.

3. The combination of a boiler shell, a back head for the boiler shell, said back head having a fire box opening, a mud ring secured to said boiler shell and to said boiler back head, and a fire box secured to said mud ring and extending into the opening in said boiler back head and secured thereto.

and removable Without removing said back head or saidniud ring, substantially as de: scribed. v v r 4. The combination with a boiler shell, of a back head extending across saidsliell and having anopening for afire box shell, a mud ring supported by the boiler shell, a fire box shell open at its bottom and seated upon and secured to said mud ring and having its rear end of larger diameter than the portion forward of said end and said end extending through and being secured in said back head opening, said fire box shell being removable through said opening, substantially as described. H

5. The combination with a boiler shell, of a back head extending across said. shell and having a, circular opening for a fire box shell, a mud ring, a substantially cylindrical fire box shell open at itsbottom and seated upon and secured to saidmud ring and having its rear end of larger diameter than the portion forward of said end and said end extending through and being secured in said circular opening, substantially as described.

6. The combination with a boiler- ,shell having a bottom opening, of a back head extending across said shell and having an opening for a fire box she'll, a m'udring secured to the boiler shell around its opening and to said back head, a fire box shell seated upon and secured to said mud ring and having its rear end of larger diameter than the portion forward of said end and said end extending through and being secured in said I V shell, of. a back head extending across said shell and scribed.

back head opening, substantially as described. j 7. The combination with a substantially cylindrical boiler shell having an opening at its bottom, of a back head extending across said shell and having a circular opening fora fire box shell, a mud ring having side members whichare fiat and lie in a plane which is radial to the axis'of said opening and the outer edges of said sidev sides of said bottom opening resting upon the inner edges of theside members of said 'inud' ring and being secured thereto, sub

stantially as described. g

V 8. The combination with a substantially cylindrical boiler shell having an opening at its bottom,'of aback head extending across said shell and having a circular opening for a, fire box shell, a mud ring having side memberswhich are fiat andflie in a plane which is radial to'the axis of said opening, and the outer edges of said side members extending along and being'secured to the boiler shell edges which extendalong the sides of said bottom opening, and a substantially cyg lindrical boiler shell having its rear end of larger diameter than the portion forward of said rear end and extending through and A 1 of the side members of said mud ring and being secured thereto, substantially as de 9. The combination with a substantially cylindrical boiler shell having an opening at its bottom, of a backhead extending across said shell andhaving a circular opening for ,afire box shell, a mud ring having" side members which are flat and lie in a plane which is radial to the axis of said opening its and the outer edges or said side members extending along and being secured tothe boiler shell edges whichextend along the s des of said bottom opening and said mud .ring having upward and outward turned ends secured to the back head of the boiler,

and a substantially cylindrical fire box shell having its rear end extending through and a being secured in said opening and having a bottom opening and having its edges along the sides of said bottom opening resting on the inner edges of the side members of said mud ring and being secured thereto, substantially as described. Y

10., T he combination with a substantially cylindrical shell having an opening in its bottom, of a back head extendingacross said shell and having a circular opening for a fire box shell, a mud ring having side members which are flat and lie in a plane which is radial to the axis of said opening and the outer edges of said sides extending along and being secured to the boiler edges which extend along the sides of said bottom opening and having upward and outward turned ends secured to the back head of the boiler, and a substantially cylindrical fire box shell having its rearend of larger diameter than the portion forward of said rear end and extending through and being secured in said circular opening and having a bottom opening and having its edges along the sides of said bottom opening resting on the outer edges of the side members of said mud ring and being secured thereto, substantially as described.

' 11. The combination with a substantially cylindrical boiler shell having an opening at its bottom, of a back head extending across said shell and having a circular opening for a fire box shell, a mud ring having side members which are fiat and lie in a plane which is radial to the axis of said opening and the outer edges of said members having a flange extending along and secured to the boiler shell edges which extend along the sides of said bottom opening, and said side members having a flange along their inner edge, and a substantially cylindrical fire box shell having its rear endextending through and being secured in said back head opening and having its edges along the sides of said opening extending along and secured to the last mentioned flanges of said mud ring, substantially as described.

12. The combination with asubstantially cylindrical boilershell having an opening at its bottom, of a back head extending across said shell and having a circular opening for a fire box shell, a mud ring having side members which are fiat and lie in a plane which is radial to the axis of said opening and the outer edges of said side members extending along and being secured to the boiler shell edges which extend along the sides of said bottom opening, and said mud ring having a forward cross member curved downward to conform to and bear against the boiler shell, and a substantially cylindrical fire box having its rear end extending through and being secured in said circular opening and having a bottom opening and having its edges along the sides of said bottom opening resting upon the inner edges of the side members of said mud ring and being secured thereto, substantially as de scribed. v

13. The combination of a substantially cylindrical boiler shell having an opening at its bottom, of a back head extending across said shell and having a circular opening for a fire box shell, a. mud ring having side members which are flat and lie in a plane which is radial to the axis of said opening and the outer edges of said side members extending along and being secured to the boiler shell edges which extend along the sides of said bottom, and said mud ring having a cross member curved downward concentric to the axis of the boiler shell, which lies perpendicular to the axis of said shell, and a substantially cylindrical fire box shell having its rear end extending through and being secured in said circular opening and having a bottom opening and having its edges along the sides of said bottom opening resting upon the inner edges of the side members of said mud ring and being socured thereto and having at its front a flue sheet extended downward and fitted to said downward-curved cross member of the mud ring, substantially as described.

14. The combination with a substantially cylindrical boiler shell having an opening at its bottom, of a back head extending across said shell and having a circular opening for a fire box shell, a mud ring having side members which are flat and lie in a plane which is radial to the axis of said opening and the outer edges of said side members extending along and being secured to the boiler shell edges which extend along the sides of said opening, a substantially cylindrica-l fire box shell having its rear end extending through and being secured in said circular opening and having a bottom opening and having its edges along the sides of said bottom opening resting upon the inner edges of the side members of said mud ring and being secured thereto, and stays extending from said side members of the mud ring upward and outward to the boiler shell, substantially as described.

15. The combination with a substantially cylindrical boiler shell having an opening at its bottom, of a back head extending across said shell and having a circular opening for a fire box shell, a mud ring having side members which are fiat and lie in a plane which is radial to the axis of said opening and the outer edges of said side members extending along and being secured to the boiler shell edges which extend along the sides of said bottom opening, a substantially cylindrical fire box shell having its-rear end extending through and being secured in said circular opening and having a bottom opening and having its edges along the sides of said bottom opening resting upon the inner edges of the side members of saidmud ring and being secured thereto, and stays extending forward and downward from the cross member of the mud ring to the lower portion of the boiler shell, substantially as described. V

16. The combination with a boiler shell, of a back head extending across said shell and having an opening for a firebox shell, a fire box shell having its rear end of larger diameter than the portion forward of said end and extending through and being-secured in said opening and having water ports forward of the back head, and a trans; verse head in the fire box shell at each side of said water ports for forming a water jacket, substantially as described. i 17. The combination with a holler shell, ofa back head extending across said shell and having an opening for a fire box shell," a fire box shell having its rear end of larger located within said boiler shell and extending along the sides and front of said bottom opening and being secured to the edges along said sides and front, and a substantially cylindrical boiler shell resting upon and secured to said mud ring and extending through and being secured in said back head opening, substantially as described 19. lhe combination with a substantially cylindrical boiler shell having an" opening at its bottom and the portions of the shell around said bottom being in the general perimeter ofthe boiler shell, a mud ring located within said boiler shell and being secured to the edges along said sides and front, a substantially cylindrical boiler shell resting upon and secured to said mud ring and extending through and being secured in said back-head opening, and stays extending from the mud ring to the boiler shell,

' substantiallyas described.

20. The combination of a substantially cylindrical boiler shell, having an opening in its bottom, an approximately cylindrical fire box shell, havingan opening in 'itsbottom, a flue sheet in its forward end, and a mud frame secured in said opening, the said fire box shell and boiler shell forming er -substantially arc shape in cross section, upward and outward from the 'mud' frame, said fire box shell extending farther back than the rear end of boiler shell, with a back head of boiler shell, having ordinary turned fianges, said back head being crescent shape and dished or tapered back, from flange connectingto boiler shell, to the flange connecti'ng tothe extended fire box shell and riveted to the fire box'shell, boiler shell, and mud frame, substantially as described.-

21. In a boiler, a crescent shape back head having: an ordinary fiange; turned forward for connection with boiler shell, and an or dinary fiangeturned rearward forconnection. with a fire box shell, said back head being tapered or bumpedout, the flange connecting to the fire box shell extending far.-

ther; back than the-flange connecting to the boilershell, and riveted and stayed to boiler shellandriveted to fire box shell, and mud frame, substantially as described.

22. In a boiler, the combination of a shell,

-armud frame, a back headof boiler shell,

a fire-box, heating fiues extending forward therefrom, inner and outer :h'eads secured inside the fire box at its rear end and spaced apart for the circulation of water between the heads, with openings cut out of the main fire box shellaround each'side down to the mud frame, for the circulation of'water between said heads, and afire hole door formed in the heads,- and which heads can be removed bodily without removing the fire box or the back head'of boiler shell and not interfere with thestaying of either head, substantially as described. a

=23. The combination of substantially cylindrical-boilershell having an opening in its bottom, anda substantially are shaped fire box shell in cross section, a substantially circular flue sheet, having heating fines ex tending forward therefrom,- a crescent shaped back head-ofboiler shell, inner and outer heads-secured in the rear end of the fire box, and a mud frame comprising an open bottom fire box, said shells being spaced apart forming the water and steam space between them, are both substantially arc shaped in cross section about the length of the fire box, said flue sheet being secured in the front portion of the fire-box, said back head of boiler shell being secured between said spaced apart shells at the rearend of the boiler inclosingsaid water and steam space at the rear end, said mud frame being secured to the arc ends of said shells on each side, and extending across between'said cylindrical shelhfire box, and flue sheet and secured thereto, the rear ends of the mud secured to said shells and .backhead, inclosing the lower portions of said water space and forming the'fire box opening, said inner and outer heads inclosing the rear end of said fire box and form the back water wall frame are turned upward and outwardand edge of door sheet flange, through flange of back head of boiler shell, and riveted to said parts, substantially as described.

opening, said boiler shell being approxi mately arc shape from the front portion a of the mud frame to the back head of boiler she'll,- a fire box consisting of a substantially arc shaped shell in cross section, flue sheet riveted in its forward end, heating flues ex tending forward therefrom, inner and outer water space heads riveted in its rear end, a solid bar of sheet metal inclosing the bottom of said heads, the fire box being riveted to the top flange of mud frame, and to the flange of back head, and forming the water space between said boiler shell and fire box, substantially as described.

26. The combination of a substantially cylindrical boiler shell having an opening in its bottom, a fire box shell substantially cylindrical or are shape, a flue sheet in fire box shell and heating flues extending forward therefrom, and a mud frame with a crescent shape back head of boiler shell having an inward turned flange riveted to boiler shell, an outer turned flange riveted to fire box shell, the bottom being riveted to the mud frame, said head being bumped out or tapered back from boiler shell connection to fire box connection substantially as and for the purpose described.

27. In a boiler a back head of boiler shell in combination with the outside shell of boiler, a fire box, and a mud frame, the fire box extending farther back than the boiler shell, said back head being bumped out or tapered back from end of boiler shell to end of fire box shell, or from its outside edge toward the center, the center extending back farther than the outside edges, substantially as described.

28. In a boiler a fire box substantially arc shape in cross section, a flue sheet in forward end of fire box with heating flues ex tending forward therefrom, forming the front end of firebox, an inner and outer head inclosing the rear end of fire box and form ing a water space therein, the said open bottom fire box being removable through the back head of boiler shell.

29. The combination in a boiler, of a fire box having an open bottom, heating flues extending forward from the fire box, with inner and outer heads placed inside the fire box shell at its rear end forming a water space between said heads, with opening cut out of said fire box shell for the circulation of water between said heads, the fire door hole being formed in said heads, and which heads can be removed bodily without removirlilgfihe firebox or the back head of the boiler s e 30. The combination with a fire box shell, a mud frame, and a back head of boiler shell, of inner and outer heads placed inside of said fire box shell'and spaced apart, forming the rear water wall of the fire box, having holes cut away above the mud frame in said fire box shell for the circulation of water between said heads, and the lower portion of said heads extending across the fire box between the side portions of said mud frame being inclosed with metal.

31. The combination in a boiler of a fire box, having a flue sheet and heating flues extending forward therefrom, a boiler shell extending over and around the sides of the fire box, a crescent shape back head secured to said boiler shell and to said fire box shell at the rear end, the said fire box shell and the boiler shell extending over and around each side of the fire box being substantially arc shape from the flue sheet to said back head, forming an open bottom for communication with the ash pan or ash pit, the space between the arc ends of said fire box and boiler shells from the flue sheet to said back head, being inclosed with metal.

32. The combination of a boiler shell, a fire box, heating flues, a mud frame and boiler stays, said stays extending forward under said flues from the front portion of said mud frame to said boiler shell, securing the front portion of the mud frame to the boiler shell, other of said stays extending upward and outward from the sides of said mud frame to said boiler shell, securing the side portion of the mud frame lying between the fire box and the boiler shell, to the boiler shell.

33. In a boiler having a fire box with a flue sheet in its forward end, heating flues extending forward from said flue sheet, inner and outer heads in the rear end of said fire box, the fire box resting on a mud frame and substantially arc shaped in cross section between said flue sheet and said inner head.

34:. The combination of a substantially cylindrical boiler shell having an opening in its bottom, a fire box substantially are shaped in cross section, a back head of boiler shell, a back head and door'sheet of fire box, a flue sheet and a mud frame, said mud frame being secured to the lower edges of said boiler shell, fire box, back head of boiler shell, back head and door sheet of fire box, and flue sheet, and removable, rearward from the boiler, without removing any of said parts.

35. The combination in a boiler of a mud frame, fire box shell, and a boiler shell ex tending over and around the sides of the fire box, said boiler shell and fire box shell both being substantially are shaped in cross section, said mud frame and said boiler shell being connected to a tapered connection or approximately frustum shaped connection,-

extending forward from the front portion of 36. In a boiler the combination of a fire Y box shell, a fiue'sheet, a combustion chamber, heating fiues, stay fines, said combustion chamber being circular in cross section and secured to said flue sheet and ofless diameter than the flue sheet, said heating fines extending forward from said flue sheet over and around each side of said combustion chamber to a suitable point from the bottom of said flue sheet, said stay fines extending forward from saidfiue sheet below said heating fiues. Y

37. In a boiler, an open bottom fire box having a flue sheet in its forward end, heating fines extending forward therefrom, inner and outer heads in its rear end,lforming a water space, said fire box being removable 'through the back head of the boilerfshell,

without removing said flue sheet and heating fiues.

38. In a boiler, the combination of a boiler shell having a back head, an open bottom,

fire box extending from an opening in the back head forward and having a flue sheet at its forward end, and heatingflues extending forward from said flue sheet, said fire box being removable through the opening in the back head of the boiler shellwithout removing the flue sheet and heating flues.

39. In a boiler, the combination of a boiler shell of cylindrical form, a fire-box of cylindrical form within the boiler shell and spaced therefrom and extending forward from and removable through an opening in said back head, said shell and said fire box having openings at the bottom that communicate with the ash pan, a flue sheet at the forward end of the firebox, and heating fines extending forward from said flue sheet. V-

40. In 'a boiler, the combination of a boiler shell having a vbackhead, a fire box within .ing in said back head and removable theresaid shell extending forward from the open- 7 through, said 'fire box having an open bottom adaptedto communicate with the ash pan below it. Y a v 41. In a boiler, the combination of a, shell having a back head, a'fire-box within the shell extending forward from an opening in the back head through which it is removable, and separated end walls in the fire box attached thereto at the rear end the space Y between them being a water space.

42. l he combination with a boilershell, a back head extending across said shell and having an opening for a fire box shell, a mud ring supported bythe boiler shell, a fire box shell open at its bottom and having a flue sheet'in its forward end and situated upon and secured to, said mudring, said fire box being removable through said back head opening. Y r Y Y 4:8. The -cor'nlgfinatiin with a boiler shell, a back head extending across said shell and having anopening therein, a fire box shell open at its bottom having heating fines extending forward therefrom being situated in the rear portion of said boiler shell, and removable through said back head opening.

CHARLES WAKEFIELD CROWELL.

'witnessesz 7 i S. P. ,ARMSTRONG, P. GEORGE.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. 0. V Y 

